The present invention relates to an internal combustion engine ignition device having an ignition plug and an ignition coil that are integrated with each other.
An ignition device of this type has a tubular metal housing, which houses the components of an ignition plug and an ignition coil. The housing is comprised of a plurality of cases, which are integrated together by all-around welding (U.S. Pat. No. 6,119,667).
The axial force of the components in the housing causes the tensile load to act on the welded portions of the cases. This requires that the welding strength be sufficient. Consequently, it is essential to control the welding strength.
It is therefore an object of the present invention is to provide an internal combustion engine ignition device the cases of which do not need welding.
According to the present invention, an ignition device is comprised of an ignition plug, an ignition coil, and a tubular housing that includes a first case adjacent to the combustion chamber and a second case away from the combustion chamber. The first case has a first flange formed at an end thereof away from the combustion chamber. The second case has a second flange formed at an end thereof adjacent to the combustion chamber. The first flange faces a side of the second flange. The housing includes a first housing portion adjacent to the combustion chamber, a second housing portion away from the combustion chamber, and a third housing portion between the first and second housing portions. An ignition plug and the ignition coil includes respective components housed in the first and third housing portions, respectively. A holder is connected to the second housing portion for fixing the components in the housing.